AGRICULTURAL. CHEMISTRY — AGROTECHNY. 211 



The determination of free sulphur in condimental feeds, stock tonics and 

 conditioners, G. M. Macnideb {Jour. Indus, and Engin. Chem., 3 {1911), No. 1, 

 l'l<- 'i-h -'I'h fig- 1; a^s. in Chem. Abs., 5 {1911), lYo. 5, p. 930).— The author 

 utilizes for this purpose a special apparatus, which consists of a graduated 

 tube ]G.4 cm. long and 3 cm. in diameter, with a stopcock fused in the tube 

 at about 5 cm. above the bottom. One gm. of the feed is placed in the tube, 

 50 cc. of carbon disulphid added, the tube stoppered, and shaken in a shaking 

 machine for 5 hours. The tube is then allowed to stand over night and 20 cc. 

 of the carbon disulphid extract is drawn off into a 450 cc. Erlenmeyer flask by 

 way of the glass stopcock. The carbon disulphid in the Erlenmeyer flask is 

 evaporated off, the residue dried in a water oven, and the residual sulphur 

 taken up with sodium hydrate. The solution is diluted, the sulphur oxidized 

 with a stream of chlorin, the solution then acidifieil, boiled to discharge free 

 cblorin, filtcrtMl, niid tlio sulplmr (U'tcniiiiicd as barium sulphate by jirix-ipitation. 



The clinical detection of glucose in the urine of domestic animals, F. W. 

 DoLz {Der llinifiche Nachweis von Traubenzucker itn Hum dcr Haustiere. 

 Inaug. Diss., Univ. Giessen, 1910, pp. lO.'i; rev. in ZentN. Gcsam. Physiol, u. 

 Path, atofficcchscls, n. ser., 6 (1911), No. 2, pp. 68, 69). — A discussion in regard 

 to the efficiency of the methods utilized for this jnirpose. 



Estimation of nicotin in concentrated tobacco juices, II. L'lex {Chem. Ztg., 

 35 {1911), No. l.'i, p. 121; ahs. in Analyst, 36 {1911), No. .}.?/, p. i.'/3).— Ten gm. 

 of the sample are weighed out in a porcelain dish and diluted with from 1 to 3 

 cc. of water. A mixture of 1 part of soda lime and 5 parts of calcined gj-psum 

 is then mixed with the liquid in sufficient quantity to produce a coarse powder. 

 This is ground in a mortar with gentle pressure, and is passed through a fine 

 sieve with about 220 meshes per square centimeter. The particles remaining on 

 the sieve are again ground with a little more of the mixture, and the process 

 rejieated until the whole has been sifted. In mixing the liquid with the soda 

 lime, the quantity taken should be such that all tendency to heating is avoided. 



The total mixture will now amount to about 50 gm. ; the ammonia compounds 

 will be decomposed and volatiliztnl, and the free nicotin remain behind. The 

 elimination of the ammonia is completed by exposing the powder over sulphuric 

 acid in a desiccator for about an hour. The nicotin is then distilled in a cur- 

 rent of steam, using a tin flask of about 3 liters' capacity. This is charged with 

 1.5 liters of water heated ahnost to boiling; the dry powder is then introduced 

 quickly, together with from 3 to 4 gm. of potassium or sodium hydroxids and 

 4 gm. of paraffin wax to prevent frothing. The flask is connected with the con- 

 denser and 1 liter is rapidly distilled off. Distillation is then interrupted, and 

 1 liter of boiling water is added to the contents of the flask, a second liter of 

 distillate being collected *in a separate vessel. The nicotin in the distillates is 

 xletermined by titration with half-normal hydrochloric acid, using litmus as an 

 indicator. 



The method, according to the author, gives good results, and no evaporation 

 of nicotin takes place during the elimination of the ammonia in the manner 

 described. While it appears to yield higher results than some of the methods 

 depending on extraction, this, according to the author, is due to the incom- 

 pleteness of the extraction, and not to a fault in the method described above. 



Determination of nicotin in concentrated tobacco juices, J. Schkoueb 

 {Chem. Ztg., 35 {1911), No. Jf, p. SO). — In this work the author points out the 

 discrepancies which occur when various methods are utilized for the determi- 

 nation of nicotin in tobacco extracts, sheep dips, etc.), and describes the Ulex 

 method noted above, which gives decidedly higher results. He criticises the 

 preference of Porchet and Regis (E. S. R., 22, p. 515) for the Toth method. 

 See also a previous note (E. S. R., 25, p. 16). 



